Tool for removing foreign matter from a well bore



Feb. 24, 1959 E. w. MGGAFFEY 2,874,781 TooL. Foa REMovINFoREIGN MATTER FROM A WELL. Boas Filed sept. 10. 195e 2 Sheets-Shet 1 uks INVENTOR.

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' I Toor. FOR REMOVING FOREIGN MATTER FROM A WELL BoRE Filedsept. 1o, 1956 v 2 sheets-sheet `2 I/a 4a. Ifo. 416.

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nd/ewan' United States Patent() TOOL FOR REMOVING FOREIGN MATTER FROM A WELL BORE Edgar W. McGaifey, Newport Beach, Calif. Application September 10, 1956, Serial No. 608,888

16 Claims. (Cl. 166-167) This invention relates to well tools of the type known as junk retrievers or junk baskets. These tools are employed for removing from well bores, foreign particles such as pieces of metal, broken parts of tools or drills and diamonds lost from drills.

lt is an object of this invention to provide an improved tool of the character which is operable responsive to manipulation of a drill string or tubing string to effect a thorough recovery of foreign particles from a well bore in a particularly efcacious and economical manner.

It is another object of this invention to provide a well tool of the character described by which foreign matter may be quickly and easily removed from a well bore without requiring that fluid under pressure be pumped down from the top of Vthe well to effect the operation of the tool.

A further object of this invention is to provide a tool of the character described wherein a reciprocal pump means having an expansion chamber, is combined in a novel manner with a tubular member for trapping foreign matter, whereby upon operation of the pump means, iiud from the well bore is rst drawn through the trapping member into the expansion chamber so as to carry particles of foreign matter into the trapping member, and is then discharged through the trapping member back into the Well bore while the foreign matter is retained in the trapping member.

It is another object of this invention to provide a tool of the character described which includes a novel means for circulating lluid in a well bore to clean out mud and sand from the well bore in preparation for operating the tool to recover pieces of foreign matter from the well bore.

Another object of this invention is to provide a cleanout tool such as described which may be repeatedly operated to assure a` thorough removal of foreign matter from a well bore by simply reciprocating the drill string or tubing string on which the tool is positioned in the well.

This invention possesses many other advantages and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown one form in the drawing accompanying and forming part of the present specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Fig. 1 is a schematic vertical sectional view of .a tool embodying this invention as it would appear when positioned in a well bore and operated to circulate uid for cleaning out the well;

Fig. 2 is a schematic vertical sectional view similar to Fig. 1, showing the position of parts of the tool when operated to induce flow of well fluid and foreign matter into the trapping member;

Fig. 3 is a schematic vertical view similar to Figs. 1 and 2, showing the position of the parts of the tool when operated to expell the fluid from the tool back into the well bore;

Fig. 4 is a vertical sectional view of the upper part of the tool;

Fig. 4a is a Vertical sectional view of the intermediate part of the tool that forms a continuation'of the part shown in Fig. 4;

Fig. 4b is a vertical sectional View of the lower part of the tool that is joined to the intermediate part shown in Fig. 4a;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4a;and

Fig. 6 is a sectional view taken on the line 6-6 of Fig. 4b.

As shown in the accompanying drawing a tool em bodying the present invention generally comprises a tubular trapping member 1 and reciprocable pump means 2 joined to the trapping member. The pump means 2 is adapted to be connected to a drill string or tubing string 3 whereby the tool may be positioned in a well bore and then operated responsive to reciprocable movement of the string.

The pump means 2 does not require that fluid be pumped thereto from the top of the well in order to be operated. It is operated solely by manipulation of the string on which the tool is positioned in the well.

In its' operation, fluid from the well bore is drawn through the trapping member 1 and into the pump means 2 so that foreign matter will be carried into and retained in the trapping member, the iiuid being held in the.

pump means Vand then discharged, back into the well bore. This operation is repeated as desired, one stroke of the p ump means eectingthe intaking of uid and foreign matter, arid the return stroke causing the discharge of the iluid back into the well while the foreign matter is retained in the trapping member.

The construction and arrangement ofthe pump means Z and the trapping member 1 are such that an expansion chamber 4 and piston means 5 forming parts of the pump means 2, are operable to create a vacuum in the expansion chamber on one stroke of the piston means. This vacuum becomes elfective in the trapping member 1, through ports 6 in the pump means, when the piston means is in a position to open the ports 6, thereby causing the well fluid to be forced rapidly into the trapping member 1 so as to carry foreign particles into the trapping member as the uid passes therethrough into the expansion chamber 4. On the return stroke of the piston means 5 the pressure of the fluid in the expansion chamber 4 causes a check valve 7 in the pump means 2 to open a discharge port 8 whereby the fluid will discharge through the trapping member 1 back into the well bore.

The trapping member 1 comprises a tubular body made up of a lower section 1a and an upper section 1b joined by a coupling member 1c having a perforated parforated partition 1d between the sections. This partition serves as a screen to limit upward movement of particles of foreign matter. The lower section 1a is normally closed at its lower end by a pair of ilapper valves 11. These valves open responsive to the operation of the pumpmeans 2 that induces llow of well iluid into the trapping member. l

A Vdischarge port 12 provided in the lower section 1a above the Valves 11 is controlled by an outwardly opening check valve 13.

Suitablel baie plates 14 are provided within the lower section 1a of the trapping member 1 to trap foreign particles carried into the member 1 with the well uid, the

bale plates being 'arranged to permit, such ow. The' perforated partition 1d prevents foreign particles from being carried upwardly'out of the trapping member 1.

The pump means 2 includes a barrel or cylinder 16, the lower end portion of which extends into the upper end ofthe upper section 1b Yof the trapping member 1. A coupling and spacing sleeve 17 welded to the barrel 16, is threaded onto the upper end of the upper section 1b of the trapping member 1 to xedly connect the barrel and trapping member, and to space them so as to provide an annular chamber 18 in the upper end of the trapping member.

The ports 6 previously referred to are in the lower portion of the barrel 16 and open into the annular chamber 18 to aiord communication between the barrel and the trapping member 1. Y v l The piston means includes a tubular piston rod member 19 reciprocable in the'- barrel 16 and carrying an annular piston 20 on its lower end.- 4This reciprocable tubular piston Yrod member is circumferentially spaced from the barrel and forms therewith the previously mentioned annular expansion chamber 4. The ends of the annular expansion chamber 4 are closed by a packing gland 21 and the annular piston 20 respectively, the gland being at the upper end of the barrel 16.

The annular piston 20 is movable from itsuppermost position shown in Figs. 1 and 4a to its lowermost position shown in Fig. 2. When the piston 20 is above the ports 6, the expansion chamber 4 is shut off from communication through the ports 6 with the chamber 18 in the trapping member 1. .However, as shown in Fig. 2, the ports 6 afford communication between the chamber 18 and the expansion chamber 4 when -the piston 20 passes below the ports 6.

A circulating valve unit 23 is coupled to the upper end of the reciprocable tubular member 19 and has a tubular cap member 24 coupled thereto. The circulating valve unit 23 includes a tubular body 25 having packing glands 26 and 27 at opposite ends. A tubular mandrel 28 is extended through the cap member 24 and the body into the upper end of the reciprocable tubular member 19. This mandrel is movable axially a limited extent relative to the cap member 24 and the body 25. The upper end of the mandrel28 is adapted to be connected as at 29 with the tubing string 3.

The valve action of the circulating valve unit 23 is provided by a pair of axially spaced ports 29 and 30 in the mandrel 28, there being a partition 31 closing the bore through the mandrel between the ports 29 and 30. When the mandrel is lowered so that the ports 29 and 30 straddle the lower packing gland 27, as shown in Fig. 2. the bore of the mandrel above the partition 31, is shut off from communication with the bore of the reciprocable tubular member 19. However, when the mandrel 28 is raised so that the ports 29 and 30 are both within the body 25 between the glands 26 and 27 as shown in Figs. l and 4, circulating fluid may be pumped down the tubing string 3 into the mandrel 28, through port 29, body 25, port back into the mandrel below the partition 31, thence down through the reciprocating tubular member 19, the barrel 16 and the trapping member 1 into the bore of the well. As the flapper valves 11 are closed when circulating fluid is pumped into the tool, the trapping member is provided with the previously mentionedV discharge port 12 and check valve 13, which latter opens to allow the circulating uid to enter the well bore as indicated in Fig. l. The circulation of uid through the tool is eiected to clean out the bore in preparation for operation of the tool to recover foreign matter at the bot torn of the bore. v

An annular stop member 36 on the mandrel 28 limits axial movement of the mandrel, being engageable with a shoulder 37 formed by the upper end of the body 25, and with an annular-member 38 of a J-lock 39 xed as by welding or otherwise within the upper part of the.

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cap member 24. The J-lock member 38 is provided on opposite sides with J-lock grooves 38a for reception of lugs 40V on 'the exterior of the mandrel 28, thereby providing a J-lock for releasably holding the mandrel and cap 24 against relative movement. The J-lock also makes it possible to rotate the tool in the bottom of the bore. In this connection, it should be noted that the lower end of the trapping memberv 1 is equipped with a serrated shoe 42 for stirring up loose material atrthe bottom of the well bore when rotating the tool.

Another J-lock 43 is provided between the reciprocable tubular member 19 and the upper part of the barrel 16 as shown in Fig. 4a. This lock comprises an annular member 43a' welded to the barrel 16 and provided with grooves 43bv for reception of lugs `43e on the member 19. This J-lock is operable to releasably lock the member 19 and the barrel and provides for rotation of the tool in the well bore.

A tubular valve cage 45 is extended through an openv ing 46 in the reciprocable member 19 and is welded or otherwise fixed thereto. The discharge port 8, previously referred to, is provided in the exposed end of the cage 45 and is operable to communicate the annular chamber 4 with the interior of the reciprocable member 19 through perforations 47 in the cage. The check valve 7 previously mentioned is mounted in the cage 45 so as to be urged by a spring 48 against a seat 49 normally to close the port 8. The port 8 opens into the expansion chamber 4 above the piston 20. The valve 7 is unseated by pressure of the uid in the expansion chamber 4 when the piston is retracted, whereby the fluid may pass through the port 8 and the perforated cage 45 into the lower end portion of the tubular member 19, thence down through the barrel 16, the trapping member 1 and the port 12 into the well bore.

In lowering the tool in the well bore on the string 3, the J-locks 39 and 43 are locked so that the circulating valve unit 23 is held open and the reciprocable member 1 9 is locked against downward movement in the barrel 16. When the tool is bottomed, circulating fluid may be pumped down the string through the tool as hereinbefore described to clean out the bottom of the bore and the tool. Fluid is prevented from entering the annular expansion chamber 4 by the check valve 7, the piston 20 and the packing gland 21.

After this clean out operation, the tool is prepared for operation by rotating the string 3 and mandrel 28 to unlock the J-locks 39 and 43, and by lowering the string and mandrel so that the circulating valve unit 23 is closed, as shown in Fig. 2. Upon now lowering the string 3, the vstop member 36 on the mandrel 28 will abut the shoulder 37 and cause the reciprocable member 19 to be lowered, thereby moving the piston 20 on its down stroke. As the piston 20 descends, fluid in the barrel 16 is forced ahead. of the piston and out through ports 6, the trapping member 1 and port 12, the valve 13 being opened bythe iluid. During this downward stroke of the piston 20 a vacuum is formed in the annular chamber 4 between the piston and packing gland 21, so that when the piston passes below the ports 6, the chamber 4 is then open to the chamber 18 and thev interior of the trapping member 1. At this time the pressure of the fluid at the bottom of the well bore causes the flapper valves 11 to open and allow the fluid to rush forcibly into the vacuum area within the trapping member 1 and chamber 4. As the uidpasses upwardly through the trapping member 1 into the expansion chamber 4, it carries into the trapping member particles of foreign matter which then become trapped by the bale plates 14.

During the down stroke of the piston 2t), the circulating valve unit 23 is closed as shown in Fig. 2, so that when the piston so passes below the ports 6, the uid in the tubing string will be prevented from gravitating through the mandrel 28 into the member 19 and trapping .member and interfering with the upward flow of well fi f t iiuid through the trapping member 1- into the chamber d. The check` valve 13 closes the instant the piston 20 passes below the ports 6 and thus renders the vacuum effective within the trapping member 1. Also at the instance of the closing of the check valve 13 the flapper valves 11 will open responsive to the differential pressures within and without the trapping member 1. i

The return stroke of the piston is effected by raising the string 3 and thereby moving the mandrel 28 and member 19 and piston upwardly in the Vbarrel 16. The mandrel 28 moves' upwardly a limited extent relative to the cap member 24 before the stop member 36 encounters the member 38. This relative movement opens the circulating valve unit 23, as shown in Fig. 3, before the member 19 and piston 20 commence their up stroke. During the up stroke of the piston 20 the ilu-id that has entered the expansion chamber 4 on the down stroke of the piston, is forced against and opens the check valve 7, then passes through the perforated cage 45, the member 19, barrel 176, trapping member 1 and discharge port 12 past the check valve 13 into the bottom of the well bore.

The reciprocation of the piston may be repeated as deemed necessary to collectthe foreign matter in the trapping member, it only being necessary to reciprocate the string 3 to eiect repeated pumping operations of the tool.

The string 3 provides for the removal of the tool with the foreign matter trapped therein, whereby this matter may be removed from the tool at the top of the Well.

I claim:

1. A -well tool for recovering particles of foreign matter from a Well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a Well bore fluid and particles of foreign matter; means in .said member for trapping therein particles of foreign matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; a piston reciprocable in said barrel; said pist-on being annular; a tubular piston rod connected at one end with said piston; said rod having an open end in communication with said trapping member; sealing lmeans at the other end portion of said barrel sealing against said piston rod; said piston rod and said barrel defining therebetween an expansion chamber closed at its ends by said sealing means and said piston respectively, said barrel having a port for communicating said chamber with said trapping member when said'piston is moved in one direction past said port; said piston shutting off communication of said chamber with said trapping member through said port when moved in the other direction past said port; said tubular piston rod having a port whichA opens into said chamber; and an inwardly opening check valve within said piston rod normally closing said last named port.

2. A well. tool for recovering particles of foreign matter from a Well bore comprising: a tubular trapping member having an opening at one end for intak-ing from the bottom of a well bore uid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; a piston reciprocable in said barrel; said piston being annular; `a tubular piston rod connected at one end with said piston; said rod having an open end in communication With said trapping member; sealing means atv the other end portion of said barrel sealing against said piston rod; said piston rod and said barrel defining therebetween an expansion chamber closed at its ends by said sealing means and said piston respectively; `said barrel having a port for communicating said chamber with said trapping member when said piston is moved in one direction past said port; said piston shutting off communication of said chamber with said .trapping member through said port When moved in the other direction past saidvport; said trapping member having a` port therein above said one end of the trapping member; an outwardly opening check valve on said trapping member normally closing said port in said trapping member; said tubular piston rod having a port therein opening into said chamber; and an inwardly opening checkY valve in said piston rod normally closing said last named port.

3. A well tool for recovering particles of foreign matter from a well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a well bore fluid and particles of `foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; a piston reciprocable in said barrel; said piston being annular; a tubular piston rod connected at one end with said piston; said rod having an open end in communication with said trapping member; sealing means at the other end portion of said barrel sealing against said piston rod; said piston rod and said barrel defining therebetween an expansion chamber closed at its ends by said sealing means and said piston respectively; said barrel having a port for communicating said chamber with said trapping member when said pitson is moved in one direction past said port; said piston shutting off communication of said chamber with said trapping member through said port when moved in the other direction past said port; inwardly opening valve means within said trapping member normally closing said opening at said one end of said trapping member; said tubular piston rod having a port therein opening into said chamber; and an inwardly opening check Valve in said piston rod normally closing said last named port. i

4. A well tool for recovering particles of foreign matter from a well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a well bore fluid and particles of foreign matter; means in said member for trapping therein particles of foreign .matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; a piston reciprocable in said barrel, said piston being annular; a tubular piston y rod connected at one end with said piston; said rod having an open end in communication with said trapping member; sealingmeans at the other end portion of said barrel sealing against said piston rod; said piston rod and said lbarrel defining therebetween an expansion chamberclosed at its ends by said sealing means and said piston respectively; said barrel having a port for communicating said chamber withV said trapping member when said piston is moved in one direction past said port; said piston shutting oif communication of said chamber with said trappingmember through said port when moved in the other direction pastsaid port; inwardly opening valve means lwithin said trapping member normally closing the opening at said one end `of the trapping member; said trapping member having a port above said one end of the trapping member; an outwardly opening cheek valve normally closing said port in said trapping member; said tubular piston rod having a port therein opening into said chamber; and an inwardly opening check valve in said piston rod normally closing said last named port.

5. A well tool for recovering particles of foreign matter from a well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a well bore iiuid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; said barrel being extended into the bore of said trapping member beyond the point 'of said connection of the barrel with said other end of the trapping `member and providing between *said trapping Vmember and said extended portion of the barrel an annular chamber; said extended portion of said barrel having a port therein opening into said annular chamber; a tubular piston'rod reciprocable in said barrel and having an open end communicating said rod with said trapping member through said barrel; sealing means at the other end of said barrel sealing against said rod; an annular piston in said barrel secured to said rod adjacent said other end of said rod; said rod and said barrel providing therebetween an annular chamber closed at its ends Iby said sealing means and said piston respectively; said piston being movable in one direction in said barrel past said port for communicating said last named annular chamber with said tirst named annular chamber; said piston being movable in the other direction in said barrel past said port for shutting off communication of said chambers with one another through said port; said rod having a port therein opening into said chamber; and an inwardly opening check valve in said rod normally closing said last named port.

6. A well tool for recovering particles of foreign matter from a well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a well bore fluid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; said barrel being extended into the bore of said trapping member beyond the point of said connection of the barrel with said other end of the trapping member and providing between said trapping member and said extended portion of the barrel an annular chamber; said extended portion of said 'barrel having a port therein opening into said `annular chamber; a tubular piston rod reciprocable in said barrel and having an open end communicating said -rod with said trapping member through said barrel; sealing means 4at the other end of said barrel sealing against said rod; an annular piston in saidbarrel secured to said rod adjacent said other end of said rod; said rod and said barrel providing therebetween an annular chamber closed at its ends by said sealing means and said piston respectively; said piston being movable in one direction in said barrel past said port for communicating said last named annular chamber with said iirst named annular chamber; said piston being movable in the other direction in said barrel past said port for shutting ol communication of said chambers with one another through said port; said rod having a port therein opening into said chamber; an inwardly opening check valve in said rod normally closing said last named port; and means connected with the other end of said tubular piston rod for connecting said piston rod with a tubing string.

7. A well tool for recovering particles of foreign matter from a Well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom yof a well lbore uid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; a piston -reciprocable in said barrel; said piston being annular; a tubular piston rod connected at one end with said piston; said rod having an `open end in communication with said trapping member; sealing means at the other end portion of said barrel sealing against said piston rod; said piston rod and saidbarrel defining therebetween an expansion chamber closed at its ends by said sealing means and said piston respectively; said barrel having a port for communicating saidV chamber with said trapping member when said piston is moved in one direction past said port; said piston shutting ot communication of said chamber with said trapping member through said port when moved in the other direction past said port; said tubular piston rod having a port which opens into said chamber; an inwardly openaar-m81 0 ing check valve within said piston rod normally closing said last named port; and means at theother end of said piston rod for connecting said rod with a tubing string.

8. A' well tool for recovering particles of foreign matter from a well bore comprising: a tubular trapping member having an opening at one end'for intaking from the bottom of a well bore fluid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel having anropen end portion connected to the other end of said trapping member; a piston reciprocable in said barrel; said piston being annular; a tubular piston rod connected at one end with said piston; said rod having an open end in communication with said trapping member; sealing means at the other end portion of said barrel sealing against said piston rod; said piston rod andsaid barrel defining therebetween an vexpansion chamber closed Vat its ends by said sealing means and` said piston respectively; said barrel having a port for communicating said chamber with said trapping member when said piston is moved in one direction past said port; said piston shutting ol communication of said chamber with said trapping member through said port when moved in the other direction past said port; said tubular piston rod having a port which opens into said chamber; an inwardly opening check valve within said piston rod normally closing said last named port; valve means joined to the other end of said piston rod operable for opening and closing said other end of said rod; and means joined to said valve means for joining said valve means to a tubing string.

9. A well tool for recovering particles of foreign matter from a well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a well bore uid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel having an open end portion connected to the other end of said trapping member; a piston reciprocable in said barrel; said piston being annular; a tubular piston rod connected at one end with said piston; said rod having an open end in communication with said trapping member; sealing means at the other end portion of said barrel sealing against said piston rod; said piston rod and said barrel defining therebetween an expansion chamber closed at its ends by said sealing means and said piston respectively; said barrel having a port for communicating said chamber with said trapping member when said piston is moved in one direction past said port; said piston shutting olf communication 0f said chamber with said trapping member through said port when moved in the other direction past said port; said tubular piston rod having a port which opens into said chamber; an inwardly opening check valve withinsaid piston rod normally closing said last named port; means joined to the other end of said rod for connecting said rod to a tubing string with the bore of the string subject to communication with the bore of said rod; and a circulating valve interposed between said connecting means and said rod operable for establishing' and shutting off communication between said rod and said string responsive to movement of said string.

l0, A well tool for recovering particles of foreign matter for a Well bore comprising: a tubular trapping member for intaking well tiuid and particles of foreign matter from the bottom of a well bore; means in said member for trapping particles of foreign matter entering said member with said Huid; pump means joined to said trapping member; said pump means including a piston, an expansion chamber and port means which cooperate upon movement of said piston in one direction, to effect said intaking of said tiuid and particles, and cooperate upon movement of said piston in the opposite direction to discharge such fluid into the bottom of the well bore; and means connected with said piston forV connecting 9 Y said pump means with a tubing stringaffordingcommunication 'of said string with said trapping member through said pump. means; said last named means including ta circulating valve operable to shut off communication between said pump means and said tubing string on said movement ofssalid piston in said one direction, and operable to establish communication of said tubing string with said trapping member on movement of said piston in said `opposite direction.

11. A well tool for recovering particles of foreign matter from' a well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a Wellbore fluid and particles of foreign matter; means, in said member for trapping therein particles of foreign matter entering said member; a barrel fixed to the other end of said trapping member; said barrel havingl one `end portion extended into and circumferentially spaced fromsaid trapping member; said end portion of said barrel having a port therein opening into said tubular member; a tubular piston rod reciprocable in said barrel; sealing means at the other end portion of said barrel sealing against said piston rod; an annular piston operable in said barrel on one end of said rod; said rod having one end of the bore thereof in communication with said trapping member; said piston being movable in opposite directions past said port; said barrel and said trapping member providing therebetween an annular chamber closed at its ends by said sealing means -and said piston, respectively; a port in said tubular piston rod opening into said annular chamber, an inwardly opening check valve in said tubular rod normally closing said port in said rod; and means connected with said piston rod for joining said rods to a tubing string and affording communication between said string and said rod; said last named means including circulating valve means operable responsive to reciprocation of said string for communicating the tubing string with said rod and l for shutting oif communication between said string and said rod.

12. A well tool for recovering particles of foreign matter from a well bore comprising: a tubular trapping member having an opening at one end for intaking from the bottom of a well bore uid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel fixed to the other end of said trapping member; said barrel having one end portion extended into and circumferentially spaced from said trapping member; said end portion of said barrel having a port therein opening into said tubular member; a tubular piston rod reciprocable in said barrel; sealing means at the other end portion of said barrel sealing against said piston rod; an annular piston operable in said barrel on one end of said rod; said rod having one end of the bore thereof in communication with said trapping member; said piston being movable in opposite directions past said port; said barrel and said trapping member providing therebetween an annular chamber closed at its ends by said sealing means and said piston, respectively; a port in said tubular piston rod opening into said annular chamber; an inwardly opening check valve in said tubular rod normally closing said port in said rod; a tubular body connected with the other end of said rod; a tubular mandrel axially movable through said tubular body; sealing means at the ends of said tubular body sealing against said mandrel; means on said mandrel affording the connection of said mandrel with a tubing string; means embodied in said mandrel for communicating the bore of said mandrel with the bore of said tubular piston rod and to shut off communication between the bore of said piston rod and the bore of the mandrel when moved into predetermined positions with respect to said body; and means for limiting relative movement between said mandrel and said tubular body.

13. A well tool for recovering particles of foreign i0 matter from a well bore comprising: a'tubular trapping member for intak-ing well u'id and particlesof foreign matter from the bottom of a well bore; means in said member for trapping particles of foreign matter entering said member with said fluid; pump means joined to said trapping member; said pump means including a piston; an expansion chamber and port means'which cooperate upon movement of said piston vin one direction, to eifect said intaking of said fluid and particles, and cooperate upon movement of said piston inthe opposite direction to discharge such fluid into the bottom of the well bore; means connected with `said piston for conecting said pump means with a tubing string; said last named means affording communication of said string with said trapping member through said pump means; `said last named means including a vcircula-ting valve operable to shut off communication between said pump means and said tubing string upon said movement of said piston in said one direction and operable to establish communication of said tubing string with said trapping member on movement of said piston in said opposite direction; means for releasably locking said piston rod and barrel against relative movement, releasable responsive to rotation of said piston rod relative to said barrel.

14. A well tool for recovering particles of foreign matter from a well bore comprising; a tubular trapping member having an opening at one end for intaking from the bottom of a well bore uid and particles of foreign matter; means in said member for trapping therein particles of foreign matter entering said member; a barrel fixed to the other end of said trapping member; said barrel having one end portion extended into and circumferentially spaced from said trapping member; said end portion of said barrel having a port therein opening into said tubular member; a tubular piston rod reciprocable in said barrel; sealing means at the other end portion of said barrel sealing against said piston rod; an annular piston operable in said barrel on one end of said rod; said rod having one end of the bore thereof in communication with said trapping member; said piston being movable in opposite directions past said port; said barrel and said trapping member providing therebetween an annular chamber closed at its ends by said sealing means and said piston, respectively; a port in said tubular piston rod opening into said annular chamber; an inwardly opening check valve in said tubular rod normally closing said port in said rod; a tubular body connected with the other end of said rod; a tubular mandrel axially movable through said tubular body; sealing means a-t the ends of said tubular body sealing against said mandrel; means on said mandrel affording the connection of said mandrel with a tubing string; means embodied in said mandrel for communicating the bore of said mandrel with the bore of said tubular piston rod and to shut oi communication between the bore of said piston rod and the bore of the mandrel when moved into predetermined positions with respect to said body; means for releasably holding said piston rod and barrel against relative axial movement; and means for releasably holding said mandrel and said tubular body against relative axial movement; said two last named means simultaneously releasing said mandrel and said piston rod for movement relative to said body and said barrel responsive to corresponding rotation of said mandrel and said piston rod.

15. A bailer for wells, comprising: a tubular trapping member for receiving well fluids and solid particles from the well; said member having an intake valve and an outlet valve; pump means for drawing fluids and solid particles through said intake valve and for expelling fluids through said outlet Valve; said pump means including a tubular housing connected to said trapping member; a tubularrplunger in said housing; said plunger and housing forming a suction chamber therebetween; means forming a seal between said plunger `and said housing; said housing having an inlet port adjacent said trapping 11 member leading from said trapping member into said 'suction chamber; and valve means in said plunger Ycommunicating with said suction chamber for'dis'char'ging iiuids from said suction chamber into said tubular 'plungi er; said tubular plunger having an open end` communicat ing with said trapping member.

16. A bailer for wells, comprising: a tubular trapping member for receiving well uids and solid particles from the well; said member having an intake valve and an outlet valve; pump means for drawing fluids and solid particlesl through said intake valve and for expelling uids through said outlet valve; said pump means including a tubular housing connected to said trapping member; a tubular plunger in said housing; said plunger and housing forming a suction chamber therebetween; means. forming a seal between said plunger and said housing; said housing having an inlet port adjacent said trapping member leading from said trapping Vmember into said suction chamber; and valve means in said plunger communicating with said suction chamber for discharging fluids from said suction chamber into said tubular plunger; said tubular plunger having an open end communicating with said trapping member; and couplingmeans at the other end of said tubular plunger for connection to a running-in string of tubing; and circulating valve means in said coupling means.

References Cited in the le of this patent UNITED STATES PATENTS 2,000,750 Gates May 7, 1935 2,041,720 Melo May 26, 1936 2,053,602 Coberly Sept. 8, 1936 2,180,935 Dumble Nov. 21, 1939 V2,659,442 Sutliff Nov. 17, 1953 2,674,318 Sutlii Apr. 6, 1954 2,701,020 Condra Feb. 1, 1955 

